The prefabricated archway of the present invention is made of a light, durable material, preferably polyurethane molding foam. This facilitates quick assembly of archways in door frames or along hallways. The cove arch of the present invention is also made of a light, durable material. A cove arch interconnects a ceiling and a side wall or is located at the top of a recessed portion of a wall used for the display of artwork or a statue.